1. Field of the Invention
The present invention relates to apparatuses and methods for testing electronic components, for example, for testing characteristics of chip electronic components such as a monolithic ceramic capacitor and a composite high-frequency component. In particular, the present invention relates to an apparatus and a method for testing an electronic component, wherein the electronic component is inserted into a cavity of a substrate and characteristics of the electronic component are measured by a probe.
2. Description of the Related Art
Various types of testing apparatuses are used in the process of measuring and testing characteristics of ceramic electronic components such as a monolithic ceramic capacitor.
FIG. 5 is a perspective view showing an example of known apparatuses for testing electronic components. In this example, characteristics of an electronic component 51 are measured with probes 52 and 53. The electronic component 51 includes a main body 51a, and electrodes 51b and 51c disposed at both ends of the main body 51a. The electronic component 51 is disposed in a cavity of a substrate (not shown) such that the electrodes 51b and 51c are arranged at the upper and lower ends of the electronic component 51, respectively. To measure the characteristics of the electronic component 51, the probes 52 and 53 are attached to the electrodes 51b and 51c, respectively, in the directions of arrows in FIG. 5. The probes 52 and 53 are easily positioned because they are attached to the electrodes 51b and 51c at the end surfaces of the electronic component 51.
However, recent size reduction of electronic components causes some problems. The probe 53, which is located below the electronic component 51, passes through a hole in the substrate to access the electrode 51c. For testing an electronic component with reduced size, the size of the cavity for accommodating the electronic component 51 is reduced, accordingly. The size of the hole for enabling the probe 53 to pass through is even smaller than that of the cavity. In this case, a general-purpose probe having a relatively large diameter cannot pass through the hole. That is, characteristics of an electronic component with reduced size cannot be measured.
Referring now to FIG. 6, the probes 52 and 53 are attached to the electrodes 51b and 51c, respectively, on the upper surface of the electronic component 51. The electronic component 51 is inserted into a cavity having an opening at the top (not shown). The probes 52 and 53 can be attached to the electrode 51b and 51c through the opening of the cavity. Testing a small electronic component, in this case, is relatively easy.
However, as the size of the electronic component 51 further decreases, the probes 52 and 53 cannot be reliably attached to the electrodes 51b and 51c, because the size of the upper portions of the electrodes 51b and 51c decrease, accordingly.
In addition, the probes 52 and 53 always require some adjustments, because the spacing between the electrodes 51b and 51c, and the size of the upper portions of the electrodes 51b and 51c vary from electronic component to electronic component.
FIG. 7 illustrates an apparatus for testing an electronic component disclosed in Japanese Unexamined Patent Application Publication No. 2001-332460 (hereinafter referred to as “Patent Document 1 ”). A substrate 61 has a cavity 62 opening at the top, and the electronic component 51 is contained in the cavity 62. A conductive plate 63 is bonded to the lower surface of the substrate 61. The conductive plate 63 has a hole 63a opposing the cavity 62. In this apparatus for testing an electronic component, the electronic component 51 is inserted into the cavity 62 for allowing the electrode 51c of the electronic component 51 to be attached to the conductive plate 63. Subsequently, the probe 64 located above the electronic component 51 is attached to the electrode 51b on an end surface of the electronic component 51. Characteristics of the electronic component 51 are thus measured with the conductive plate 63 and the probe 64. In the apparatus for testing electronic components disclosed in Patent Document 1, a plurality of the cavities 62 are provided on the substrate 61, and the conductive plates 63 are arranged so as to extend to the lower surfaces of all of the cavities 62.
Even if a small-sized electronic component is tested, the conductive plate 63 is reliably attached to the electrode 51c of the electronic component 51, while the probe 64 is easily attached to the upper electrode 51b. 
Since the conductive plates 63 arranged under the cavities 62 are shared by a plurality of electronic components, however, use of this testing apparatus is limited to measurement of particular characteristics, such as insulation resistance, that can be measured even when one of the electrodes of the electronic component is shared with other electronic components. In other words, the apparatus for testing electronic components disclosed in Patent Document 1 cannot be used to simultaneously measure characteristics, such as capacitance, that cannot be measured when one of the electrodes of the electronic component is shared with other electronic components.